About 40 Taiwanese fishing boats and 12 patrol boats entered waters near the islands on Tuesday morning, briefly triggering an exchange of water cannon fire with Japanese coast guard ships. Coast guard officials said the Taiwanese vessels had ignored warnings to get out of their territory, and the Taiwanese ships pulled back after being fired upon.

It was Taiwan's first foray into the waters around the uninhabited islands, known as Senkaku in Japan and Diaoyu in China, since the Japanese government purchased some of them from private owners two weeks ago. China, Japan and Taiwan all claim the islands, but they are administered by Tokyo.